The present invention relates generally to the material handling art and, more particularly, to an improved apparatus for fixedly locating and locking a glass bending mold in place on a continuous conveyor.
One well-known expedient for bending glass sheets, such as those intended for use as glazing closures in automobiles and the like, utilizes a ring or skeleton-type bending mold having shaping surfaces adapted to engage and support only the marginal edge portions of the sheets to avoid marring the central viewing area of the finished glazing closure. According to this technique, a flat sheet of glass is supported on such a so-called "gravity-type" mold above the shaping surface and is heated in the furnace to a temperature corresponding to the softening point of glass, whereupon the sheet sags by gravity into engagement with the shaping surface of the mold. While the bent sheet is still resting on the mold after being shaped to the desired configuration, it is annealed or tempered, as desired, in a controlled manner by subjecting the sheet to a chilling medium, such as streams of cooling air for example. In a mass production operation, the glass-laden molds are advanced along a predetermined path on a continuous conveyor system through a furnace for effecting the heating and bending of the sheets and then through a contiguous cooling area for annealing or tempering the bent sheets. Conventionally, the sheets were loaded and unloaded manually by hand.
In order to avoid these manual loading and unloading operations and to promote efficiency, an apparatus, such as that described and claimed in U.S. patent application Ser. No. 238,452, filed Feb. 26, 1981, has been developed to automatically load flat glass sheets, including paired sheets of glass, on these gravity-type molds and to unload or remove the bent glass sheets therefrom. A mold locking arrangement is also disclosed in the aforesaid patent application Ser. No. 238,452 to temporarily stop and position a mold on the conveyor in vertical alignment with the glass loading and unloading apparatus. While this mold positioning arrangement has admirably served the purposes for which it was designed, it possesses certain shortcomings. For example, the mold locating mechanism includes a pair of locking heads that protrude above the level of the conveyor system to form undesirable obstructions that can cause mold jam-ups when the advancing molds are misaligned or inadvertently disposed in an askewed orientation on the conveyor and when they are laterally offset or otherwise misaligned from their intended path of movement. Also, these protruding locking heads can interfere with glass cullet removal.